The invention relates in general to a method and apparatus for processing images of a tissue sample microarray made up of a plurality of tissue microarray dots using an optical microscope. More particularly, the invention relates to a method and apparatus for capturing tissue sample images from the tissue sample microarray, indexing such images and manipulating and transmitting them.
It is known that in the treatment and prevention of cancers it is often important periodically to examine persons at risk for cancer. In some instances it may be necessary to biopsy tissue from such persons. As medical care has become available to more people and as the need for such increased vigilance has been recognized, the number of biopsies has increased.
One of the problems with evaluating biopsy materials is that in most cases microscopic evaluation of cellular structure and tissue architecture has been important in making determinations as to whether cellular changes have occurred in tissues indicative of cancer or whether cancer is actually present. In the past, such determinations have been made by employing microscopic examinations of tissues and associated cellular structures.
A number of techniques have been developed, including techniques developed by the present inventors, for providing greater accuracy and throughput for such biopsy systems.
In one such system tissues from a particular patient which have been stained are positioned from a particular patient on a microscope slide and are imaged by a light microscope. The images are captured and digitized in a tiled format. The tiles can be reassembled substantially in real time to create pan and scan images of large amounts of tissue at high magnification while simultaneously providing a second digitized image of tissue at low magnification to provide a guide to regions of interest of the pathologist. This system has proven to be a boon to pathologists.
Improvements made upon that system, such as that disclosed in U.S. Pat. No. 6,031,930 to Bacus et al., are directed to further enhancements of the microscopic image examination in that detailed features of the morphometry of images of microscopic objects, such as cells, cell fragments, and the like, are made more easy. Statistical measures are applied which are highly discriminating for neoplasia across diverse tissue types, such as breast, colon, cancer, cervical tissue, and the like. In addition, such systems are valuable in providing assaying functions for different carcinogens and chemopreventive agents.
More specifically, such systems use microscopic images of stained neoplastic tissue sections which are microscopically scanned to provide electronic or digitally recorded. Morphometric features of tissue sample images are measured in first unit values and texture measurements of the tissue samples, such as a Markovian texture measurement, are also made. The respective results are recorded on a grading common scale so that progression of cancer can be ascertained relative to normal tissue.
An additional advance has been made, as exemplified by U.S. Pat. No. 6,101,265 to Bacus et al. Bacus et al. disclose the use of an imaging system which can scan stained tissue samples on microscope slides and generate tiled images thereof. The system also provides low and high magnification image pan and scan capability both locally and remotely. Typical magnifications are 1.25 power, 4 power, 20 power, and 40 power. This allows a pathologist at a remote site to be able to examine a complete and accurate magnified record of the tissue. This can occur over a packet network, such as the Internet or the like, without the need for a wide-band, high-speed transmission, such as a television line.
Despite each of the advantages which have been provided by the previous systems, they still have some drawbacks when presented with newer technologies for rapid assay of large amounts of tissue. Recently, molecular profiling of tissue specimens has come into wider use. This process has to do with the discovery of new genes and targeting genetic probes for attachment to particular tissue regions and molecules such as epitopes. Pharmaceutical companies and researchers in the biological sciences are interested in developing antibody-based probes using standard antibody staining reactions in order to detect molecular abnormalities on the surfaces of cells.
In order to assay such wide collections of patients, it is necessary to collect large amounts of data from the patients. It is known to prepare tissue sample microarrays which consist of a plurality of circular sections of tissue drawn from a variety of persons or sampling sites and placed on a single microscope slide. Such samples are prepared by taking a very small diameter punch, removing punch cores of tissue and placing them into open columns in a paraffin block which open columns are arranged in a grid type array which may for instance have two to three hundred columns available. The total size of the block is small enough that an end section of the block would conveniently fit on a microscope slide under a cover glass or cover slip. Once the columns of tissue are placed within the block, the block is further treated so that the paraffin invades the tissue to provide a typical paraffin biological specimen. The block may be sectioned using separate microtome sectioning techniques and the sections with the two to three hundred circular tissue sample “dots” may be placed on a microscope slide.
The slide may be subjected to staining and other antibody treatment and has the particular advantage that all two to three hundred of the specimens in the microarray are subjected to simultaneous and identical staining conditions, temperature conditions, and the like, so that variables need not be controlled for between patients who are being examined and a standardized treatment as applied to the tissue.
One of the problems, however, with such microarray-based assays is that the slides must be processed by hand. A microscopic determination must be made of characteristics of each of the tissue samples. At times tissue dots may fall off the slides opening up voids in the array or grid. It is easy for researchers who are examining the slides to lose track of which piece of tissue is being examined.
Although the microarray staining techniques have provided a considerable advantage in speeding up molecular assaying, the analysis of such results continues to be time-consuming and may be subject to more increased error than other types of assay systems.
What is needed then is a system which would provide for rapid assay of a microarray by an operator so that the advantages of bulk microarray treatment techniques can be fully realized.